Exposure limits, unprotected

Agent exposure limits as established by the Army Surgeon General (Figure 4) for unprotected personnel, dictated the requirement for monitoring and detection systems with a fast response time. 

Figure 4. Unprotected personnel exposure limits. Production worker exposure...

OSHA uses the term Permissible Exposure Limit (PEL) to define the maximum concentration of a listed contaminant to which an unprotected worker may be exposed. 

Several government regulatory agencies have taken action to protect people from excess exposure to hydrazines. EPA considers hydrazine and 1,1-dimethylhydrazine to be hazardous air pollutants. The Occupational Safety and Health Administration (OSHA) limits the amount of hydrazine and 1,1-dimethylhydrazine to 0.1 and 0.5 ppm, respectively, in workplace air for an 8-hour workday and notes the potential for skin absorption in unprotected individuals. The National Institute of Occupational Safety and Health (NIOSH) recommends that the levels of hydrazine and 1,1-dimethylhydrazine in workplace air not exceed 0.03 and 0.06 ppm. 

In cases of accidents or incidents, it is likely that a situation of increased exposure wiU occur. If this happens, the employer has the duty to inform the workers about this event. As long as the situation has not been restored, the number of workers has to be limited to those necessary to do repair work. All other persons who are not needed have to leave the work area. For those who stay within the endangered zone, the employer has to provide suitable personal protective equipment (PPE), such as suits or respirators, which have to be worn by the workers. Because the use of PPE itself can cause special risks to health, it is not permitted to use it longer than absolutely necessary. Of course, unprotected workers are not allowed to enter the zone of risk. 

Hearing protectors should be chosen to reduce the noise level at the wearer s ear to below the recommended limit for unprotected exposure (e.g. to 85 dBA which is a practicably achievable figure in almost all industrial situations). This cannot be done from simple A-weighted measurements of the noise level, because sound reduction will depend upon its frequency spectrum. Octave band analysis will provide the necessary information to be matched against the overall sound attenuation of different hearing protectors which is claimed by the manufacturers in their test data. 

Accidental exposure to a highly radioactive source such as °Co can affect the whole body but the greatest risk is to limited areas such as the hands from handling unprotected sources. 

---